What is endocarditis?
Endocarditis is an infection of the endocardium, the envelope that lines the cavities as well as the heart valves, due to the presence of bacteria. Although endocarditis can affect the endocardium of all heart valves, the most commonly affected valves are the mitral and aortic valves.
What causes endocarditis in dogs?
The bacteria that cause endocarditis come from a primary infectious focus such as pneumonia, dental infection, infection of the urogenital system (prostatitis, pyelonephritis, metritis), d dermatitis or even chronic digestive lesions.
Some dogs are more susceptible to endocarditis than others. This is particularly the case for medium to large breed dogs such as Golden Retrievers, German Shepherds, Dobermans, Labradors, Boxers or even Rottweilers. Adult male dogs are more often affected than females.
Dogs that suffer from aortic stenosis or chronic diseases are also at greater risk of developing this condition, due to the heart damage that this anomaly generates.
What are the symptoms of endocarditis in dogs?
The signs of endocarditis are often non-specific early in the course of the disease. Affected dogs may then show signs such as depression, anorexia and weight loss.
They may also develop signs related to the spread of bacteria in their body, such as fever and lameness.
At a more advanced stage, endocarditis affects the functioning of the heart, which can manifest itself in signs of heart failure, such as coughing, severe fatigue, exercise intolerance, heart rhythm disorders and respiratory disorders.
When the particles generated by the body's infection reach the bloodstream and block the blood vessels, septic emboli can also occur in the kidneys, spleen, central nervous system, intestines, skin or even the coronary artery. We then observe the appearance of other symptoms such as neurological disorders, gastrointestinal disorders, skin and/or eye damage, etc.
There are also over-acute forms of endocarditis which can progress to sepsis and be fatal for the animal in just a few hours.
How is endocarditis diagnosed?
In case of endocarditis, it is likely that your veterinarian will hear a heart murmur during the auscultation of your pet. This “heart sound” then indicates to him an abnormal blood flow at the level of a heart valve. He is, however, inconstant.
The diagnosis of endocarditis is often quite difficult to establish for your veterinarian who may have recourse to several additional examinations among:
- a blood culture which consists of a sample of venous blood, which is then cultured to look for microorganisms.
- an echocardiography which allows to visualize possible valvular lesions as well as ventricular dilation.
There is no real screening test for this condition. The definitive diagnosis of endocarditis is based on the number of diagnostic criteria for endocarditis that the dog exhibits.In other words, if your dog has more than one of these criteria, this indicates a high probability of the disease and justifies the establishment of treatment.
How is endocarditis treated?
The goal of the treatment is to treat the primary cause of the infection and then, in a second step, to treat the complications and in particular heart failure if present. Hospitalization of the dog may be necessary for acute forms.
Endocarditis is treated with long-term broad-spectrum antibiotic treatments. These antibiotics are obviously aimed at eradicating the infection and are often continued for 4 to 6 weeks. They are generally administered in injectable form during the first week of treatment and then orally thereafter.
The choice of antibiotics is first empirical and then based on the results of an antibiogram, which can help determine the most effective antibiotic for a given type of germ.
Control blood cultures are generally carried out throughout the treatment and 2 to 4 weeks after the end of the treatment in order to assess its effectiveness.
Treatment may also include pain medication as well as medication to treat heart failure.
Unfortunately, the prognosis for endocarditis in dogs is generally quite poor although it varies depending on factors such as the heart valve affected, the infectious agent in question, the state of general he alth of the dog as well as the rapidity of the diagnosis and the implementation of the treatment. A dog with endocarditis usually only survives a few weeks to a few months after diagnosis.